Electromagnetic fluid pump



Elli-11 SR 00!..13, 1953 GODBOLD 2,655,107

ELECTROMAGNETIC FLUID PUIP Filed Sept. 1, 1950 WIN-S19E75: INVENTOR.

Patented Oct. 13, 1953 2.055.107 saac'rnomscna'rro ramp rum Nat H. Godbold, Idaho Falls, Idaho; assignor to the United Statc's'of America as represented by the United States Atomic Energy Commission Application Septembcr 1.1m, Serial No. mess This invention relates to electromagnetic fluid pumps in which an electrically conducting fluid is impelled along a channel by the force which results from the reaction between anelectric current passing through the fluid and an im-' pressed magnetic held.

8 Claims. [CL 1.3-1)

In general, the electromagnetic fluid pump is old in the art and is shown, for example, in Patent .2,397,785 to Freidlander and in Patent melon tit-crumb. Such pumps of the prior art develop an impelling pressure head by the reaction between an electric current passing through the fluid normal to. the direction of fluid flow andan externally impressed magnetic fleld. This arrangement requires the use oi fluid contacting conductors on opposed edges of the fluid duct.

In certain applications the use of a fluid duct having opposed electrical connections is awkward and involves unnecessary complexity in arrangement. Hitherto it was accepted as a basic necessity in electro-magnetic fluid pumps that the connections to the fluid must be across opposed sides of the fluid duct in order that the resulting current will have a component direction perpendicular to the direction of fluid flow.

The present invention is predicated upon the discovery that the connections to the conducting fluid in an electromagnetic fluid pump can be aiflxed with a longitudinal separation to one side of the duct. Such an arrangement has a nmnber of advantages. One advantage lies in the choice of spacing between the connections to the fluid or to the fluid duct so as to obtain a more emcient coupling between the load and energization source impedences. Further, it is feasible with a pump fabricated in accordance with the teachings of this invention, to support a plurality of fluid ducts on a supporting wall or bulkhead and detachably support the magnetic structure so as to straddle the duct. Such an arrangement would involve -a number of complexities in mounting the ducts of the prior art due to interference with the leads on at least one sideofthe duct.

It is accordingly a primary obiect of this invention to provide an electromagnetic fluid pump of simpler construction and more efllcient operation than those hitherto known.

Other objects and advantages will appear from a description of a preferred embodiment oi the invention illustrated in the drawings accompanying and made a part of the specification.

In the drawings:

l 'igurclisaperspectiveviewoi'apreferred embodiment of the invention.

Pigure2isachartshowingthev'ectorrelationship between the current in the fluid and the impressed magnetic fleld oi the embodiment ot-l"igure 1. I

Referring to Figure l, the electromagnetic fluid pumps arranged in accordance with this invention comprises two mainparts whichgsre the magnetic assembly 9 and the fluid duct".

The magnetic assembly can be either a permanent magnet or'an electromagnet and it is preferably an alternating current electromagnetr To this=end the core I! is of laminated magnetsteel construction. An energizing coil It surrounds at least one leg of the core.

In order to produce a flow force on a conducting liquid in duct II, a pair of contacts it and it are provided. These contacts penetrate the duct if the duct is of dielectric material. or are simply connected to the outside surface if the tube is of conducting material. It has been found that thin non-magnetic high electrical resistivity metal such as stainless steel is preferred for the fluid duct.

The electrical circuits for either direct or alternating source energization are completed by connecting one lead ll of the electromagnet coil to one of the duct contacts. In the drawing this connection is to contact I. The remaining lead I! of the electromagnet coil it is adapted for connection to an energization source. For convenience in completing the electrical circuit a lead It is connected to fluid duct contact ll.

Although the principles of operation is not known for certain, it seems reasonable to assume that the current in the fluid diverges i'rom contact It and consequently establishes a component of current flow which is normal to the direction of migration of the fluid. Thu assumption appears sound in that it has been foimd that optimum pumping action is obtained it the contact ll under the pole piece is in the middle of the magnet fleld and the remaining contact I! is well away from the magnet fleld. The geometry of the magnetic fleld and electric current in the fluid is shown substantially in Figure 2. The dash lines represent the electric current flow in the liquid. The dash-dot lines represent the equivalent single current. Under the conditions shown, with the current entering the left hand endof the current path, and with a magnetic flux having poles as indicated by N and sit is seen that the reaction force F is to the right andthatthefluidwillbeimp llediromlcit to right: It is understood that the direction of current flow and direction of magnetic flux are mattersoiseiectiontobeexercisedbythose 3 skilled in the art to suit any particular pumpin problem.

An lectromagnetic device has been thus far described as a pump. but it is to be understood that it has the characteristic of reversibility. That is to say. if no potential. is applied to the fluid or fluid duct, and the fluid is propelled, a potential appears between the connections which is substantially proportional to the rate 01 flow. It follows that the device is adapted to be used either as a pump or a flow meter.

An electromagnetic fluid pump has herein been described with reference to what is considered to be the best embodiment thereof, but it is to be understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. The invention is therefore to be limited only by the limitations or the accompanying claims when interpreted in view of the Prior art.

What is claimed is:

1. An electromagnetic fluid pump comprising a magnetic structure having-opposed pole pieces and a fluid duct, means for supporting said fluid duct between said pole pieces, first means for connecting the terminal of an electric energy source to said duct between the pole pieces, and second means for connecting the other terminal oi the electric energy source to the fluid duct remote from said pole pieces at a position on the perimeter of the duct similar to that of the first means.

2. An electromagnetic fluid pump comprising an electro-magnetic structure having a pair or pole pieces and a fluid duct. means for supporting said fluid duct between said pole pieces. a connection to said fluid duct under said pole pieces. a second connection to said fluid duct on the same side of said fluid duct and longitudinally spaced from said first connection, a winding on said electromagnetic structure. means for connecting one end of said winding to one of said fluid duct connections and means for connecting an electrical energy source between the other end of the electromagetic coil and the other fluid duct connection.

3. An electromagnetic reaction device comprising a fluid duct, means for traversing said fluid duct with a magnetic fleld. means for establishing an electrical circuit across a length of the fluid in the longitudinal direction or said duct between a flrst point traversed by the magnetic fleld and a second point on the fluid duct remote from the magnetic fleld.

NAT H. GODBOLD.

References Cited in the flle of this patent UNITED STATES PATENTS Number Name Date 1,660,?! Bainbridge Feb. 28, 1928 2,199,866 Alterthum et al May 7, 1940 2,224,982 Morin Dec. 17, 1940 2,282,401 Hansell May 12, l942 2,386,369 Thompson Oct. 9, 1945 2,539,215 Weil et al. Jan. 23, 1951 2,131,841 Tama Feb. 13, 1951 

